Problem: Fourteen years of civil war in Liberia have devastated the nation's infrastructure and economy. It is estimated that over 250,000 people of the country's 3.5 million (over 7% of the population) were killed in the war. The majority of youth in Liberia-both combatants and civilians-have been exposed to high levels of violence. Past psychological trauma, high levels of psychiatric disorders, substance use and risky and transactional sex all put youth in Liberia at significant risk for HIV infection. Aims: In partnership with the Liberian Ministry of Health and Social Welfare, Mother Patern College of Health Sciences, and Medecins du Monde, this proposal will develop, culturally adapt, and pilot test a group-based intervention integrating HIV prevention and mental health for Liberian youth to: (1) increase adaptive coping and health-promoting behavior; (2) decrease maladaptive coping strategies such as high-risk sexual behavior and substance use; and (3) decrease traumatic distress, depressive symptoms and social-isolation. Methods: This research proposal aims to: (1) Develop a group-based mental health and HIV prevention intervention. We will develop a conceptual model to guide intervention development based on 20 key informant interviews with health care workers, religious leaders, educators, elders, and other youth leaders and 40 interviews with Liberian youth (20 male, 20 female) to identify key problems facing youth, as well as potential solutions and barriers. Based on this conceptual model, we will develop a treatment manual culturally-adapted to the Liberian context, clinician training material, satisfaction scales, and quality assurance and process rating scales. (2) Pilot test the group intervention with 80 Liberian youth (40 male, 40 female) who exhibit traumatic stress symptoms to establish preliminary evidence concerning the intervention's feasibility, acceptability and effect in reducing HIV-risk, traumatic stress and depressive symptoms, and increasing adaptive coping. Significance: The legacy of trauma increases HIV-risk for war affected youth. In Liberia, extreme poverty, traumatic stress, substance abuse, sexual and gender-based violence, transactional sex, the lack of health infrastructure, and the lack of HIV prevention programming increase the vulnerability of youth to HIV infection and transmission. Integrated mental health and substance abuse treatment is required for these individuals to fully benefit from HIV prevention interventions. However, Liberia currently lacks both (1) culturally appropriate, evidence-based mental health interventions to address trauma, substance use, and HIV risk behaviors; and (2) health care workers trained to address the consequences of trauma and loss due to the war. Developing an effective intervention integrating HIV prevention and mental health could have a significant impact in Liberia as it develops its mental health policy and expands its professional capacity in HIV prevention and mental health services, as well as relevance to other countries in the region, such as Sierra Leone, Guinea, and Cote D'Ivoire which share similar histories of violence and trauma and large populations of vulnerable youth.